Generally at the bottom part of the object, which includes hospital bed, cart, handcart, mechanical equipment, furniture, chair and 4-wheeled hand cart etc (hereinafter called as ‘cart’), at least more than one castor is installed provides ease transfer of objects including person.
The above castor is, for example, a domestically registered caster in utility model registration No. 20-0396105 (registered Sep. 1, 2005), which is equipped with a wheel, that performs rotation with/without 360° plane rotation centrally supporting shaft, and the mounted brake system of the castor performs brake through hindering of rolling motion of the wheel, which is the method of increasing friction by pressurizing surface of wheel in large.
Therefore, as the above brake system is a plane rotation structure with/without circling according to wheel, and has a negative effect of hiding inward according to moving direction of cart, when trying to brake or to release brake, man must experience inconveniences and troubles to find hidden casters inward of cart with pushing or rotating cart, moreover in worse, for example if the place were too narrow or low, then must have quite difficulties to pull the hidden castor out by hand or put some work tool into the bottom of cart.
Furthermore, in case of fixed type castor, which only requires driving straight ahead, can brake wheel with one brake system, while in case of rotating type castor, which is feasible for 360° plane rotation, has some inconvenient problems to use because of its structural characters, that one brake system to brake castor supporting shaft and another brake system to brake wheel are mounted respectively.
Furthermore, as its structure is to brake by the method of increased friction in large through pressurizing surface of wheel with friction pad of brake system, when braking it is required of braking pressure as considerable force, and also for releasing of braking power it is required considerable force too, so it is not only inconvenient, but also full of troubles frequently.